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[ Game Theory ] Dissecting The Last of Us’ Infected

Ophiocordyceps unilateralis. Before I played The Last of Us, I’d only heard of this in passing; it’s a fungus that seems to spread among ants through spores in the air. The spores, once taken in by a host ant, slowly start growing inside the ant until its baser functions are overridden, presumably to benefit the fungus somehow, until the host gives up, the fungus takes over, and takes the host to a very specific spot where it is left to die, sprout several stalks which then release spores from which other ants would be infected. The process is still mostly a mystery to us and it’s been known to take out whole colonies of ants and acts in a very specific manner. What we do know is that it infects the ant, takes over basic motor function, only to drag it to a very specific area so that way it can spread its spores. All the details inbetween are difficult for us to understand at this point and, frankly, it’s kind of scary that such a thing exists.

In The Last of Us, this fungus exists and has mutated in such a way that it takes over humans to the same purpose. While it seems obvious what the end result is, physically, there’s a lot of questions raised in-game about what the infection really is and what happens to humans when they become infected. I’ve brushed off an article type that I rarely get into, game analysis and theory, to break this one apart and see if I can answer these questions. To understand the infection, you have to start from what is plainly obvious – the progress and stages of the infection, of which there are five known types:

all runners, aside from the clicker bringing up the rear.

The Runners

Perhaps the most recognizable form of the infected, the runners have retained most of their humanity. They still have most of their motor function and the fungus has only started destroying their psyche: when the spores are inhaled, they dissolve and start spreading throughout the body, releasing into the blood and taking root in the brain. Cordyceps has only one purpose: to spread and thrive and that is the first instinct implanted into the brain as it starts breaking down the personality of the infected. Runners will thrash about, not totally understanding the commands being sent by the fungus, running at the nearest target, torn between the commands being grafted on and the need to be released from the infection. This tear in their minds, as it’s slowly being overwritten, causes a great amount of torment in the infected and it’s clear – even in the picture above – that the runners are tormented.

They seem a lot like the “zombies” from 28 Days Later, also affected by a pandemic and not reanimated from the dead. While the two are driven by two different instinctual needs, two things need to be noted: there is still very much a human being beneath the infection at this point and the basic need to spread the infection is prevalent. This stage takes place within the first two days of infection, spreading quickly and taking root in the psychosis almost immediately, depending on the nature of infection; it seems to spread quicker from a bite than from breathing in spores, as a bite eliminated the need to dissolve and, as such, can take a direct route to the important parts of the body needed to take root.

As I’ve implied, I think it’s this stage that’s caused people to associate the pandemic with zombies: the infection spreads best through bites and the infected lose most of their motor skills and personality.

a stalker that has almost become a clicker.

The Stalkers

This one’s kind of hard to differentiate between the others as it’s a kind of middle-point between the clickers and the runners. There’s no set time between when an infected becomes a stalker – it would appear that the willpower, strength of body and mind, and health seems to affect the time lapse of infection. Stalkers are especially deadly because they start developing traits and abilities of clickers without the total loss of motor function and perception, making a sort of hybrid.

What’s most important to note, here, is the growth that starts forming on their head. The actual purpose of this growth isn’t actually stated in the game or any in-game literature but there’s a few things I’ve considered: first and foremost, photosynthesis, the conversion of light into energy for a plant, meaning a plant would expose itself in a way so that it can convert light into energy; the Wikipedia article for this brand of cordyceps state that it fortifies the structure of ants in some way while taking root, meaning that this could serve as some kind of cushioning or armoring for the body; it is commonly believed in some circles that human senses only cloud the human mind to what’s really important, meaning that this growth would actually take away senses that the fungus actually knows will only get in the way. Whatever its purpose, be it a mixture of those three things or none of them at all, is never fully explained.

the last stage for many infected; the clicker.

The Clickers

Characterized by the clicking noise they make in order to exhibit echolocation – making use of the few senses they have left to locate their pray and attack. The brain has degenerated to a point where it’s almost entirely consumed and overwritten by the fungus – this means that sensations of pain are gone, emotions are lacking, and the only portion of humanity left is a portion driven completely insane: somewhere between where a stalker becomes a clicker, the infected retains a sense of survival and soon the fungus and infected become codependent on one another. At this point I still believe that there is still a sense of humanity in the infected, at this point, though it’s in shambles – it has been driven mad by the fact that in order to continue living it has to be the fungi’s willing puppet. So much so that when it finds a living being nearby it goes into a rage without consideration of the life it’s about to take.

Some have stated that the attacks – bite-driven, most times – are driven simply to spread the infection; though, to me, there seems to be a bit of hostility there: if you’ve ever died at the hands of a clicker, you’ll see that they simply don’t bite to spread the infection but rather they take a chunk right out of the victim’s neck. They are biting to kill. That makes me believe there is a sense of humanity still left, still hanging on, but barely there and, by this point, symbiotic with the fungus.

a bloater: the true monstrosity.

The Bloaters

In very few of the infected does the fungus – or injury – not kill them. In these, the fungus continues to grow to the point where they are more plant than man, becoming something Joel and a friend called “bloaters”. These infected have grown to the point where their entire body is covered in fungal growth, serving as a kind of protection but also gives it strength via photosynthesis. The bloaters seem to rely on a kind of spore bomb that is produced from these growths, which the bloater launches at its target – which seems to harm and not infect. This is interesting because the goal of this version of the infected, yet again, has changed its instinctual priority. Before, driving the infected mad was key to spreading the infection – through its flailing attack, an infected was able to spread the infection by opening a wound on a victim and coming into contact with spores, presumably from the attacker. Clickers, though, seemed to change its priority to growth maturity and self-defense. Bloaters, however, seem to take this priority to becoming entirely offensive and spreading a type of spore that does not infect the victim but harms them in some way. This could have been an oversight by the writers but somehow I doubt it.

I would assume that the symbiotic relationship between the fungus and the infected has grown to the point where its rage is pointed in a different direction: the human and fungus need each other, now, and the fungus has created such growth that it doesn’t have to worry about very much physical harm anymore. What’s left of the humanity in the infected is nearly gone, at this point, possibly driven to such a point in their insanity that they want to kill all they see that isn’t them. This role has made them extremely dangerous.

what’s left.

The Dead

When the infected has succumbed to injury or has grown too weak as a result of the infection, they move to a very specific area to, basically, shed their human form in order to grow spouts which burst at its full growth, releasing spores into the air. Large groups of the infected dead can cause problems for those passing through as they usually choose dark, humid, and closed-in areas to discard themselves in. These areas actually attract some of the nearby infected, as it tells them this is an ideal place to discard of their humanly form.

It would seem that, injury not included, the willpower and strength of heart can keep an infected alive as it matters not to the fungus whether the human can be used as a host – it takes root in the most ideal spot and spreads its spores to find a stronger host. What question this begs is this: is the fungus really just trying to reproduce or is there some kind of larger scheme at play, using humans as drones? It’s hard to say.

this is the kicker:

Great Big Spoiler Alert

The evidence behind most of my thoughts in this is in that Ellie carries the infection and yet does not succumb to the infection. How this is done is not really explained but the plain fact is that her body has rejected the spores. Humanity was quick to evolve past this naturally occurring pandemic and I believe it has something to do with the metabolism, somehow: causing the spores to die before they get a chance to get through the nervous system and into the brain. I’m no chemist but it’s either that or something in her blood – a kind of natural defense against the spores.

In conclusion, I seriously believe that the infection does not take over the human body completely but rather creates a kind of symbiotic relationship with the host, a codependency, making the human host, eventually, rely on the fungus to carry on its common goal. It’s really interesting to think about this and incredibly scary but there it is… my thoughts.

6 thoughts on “[ Game Theory ] Dissecting The Last of Us’ Infected”

The cordycep has already grew around the brain and is still alive. It seems to me that the more likely reason for Ellie’s immunity has something to do with her brain unresponsive to the cord’s neuro chemical (or somehow the neuro chemicals were disabled), therefore disabling the cord from progressing to the next stage